Initial commit

This commit is contained in:
Zhongwei Li
2025-11-30 08:32:07 +08:00
commit 555bb31091
133 changed files with 54100 additions and 0 deletions

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from dataclasses import dataclass
import json
import sys
# Script to check that the `fields.json` file that Claude creates when analyzing PDFs
# does not have overlapping bounding boxes. See forms.md.
@dataclass
class RectAndField:
rect: list[float]
rect_type: str
field: dict
# Returns a list of messages that are printed to stdout for Claude to read.
def get_bounding_box_messages(fields_json_stream) -> list[str]:
messages = []
fields = json.load(fields_json_stream)
messages.append(f"Read {len(fields['form_fields'])} fields")
def rects_intersect(r1, r2):
disjoint_horizontal = r1[0] >= r2[2] or r1[2] <= r2[0]
disjoint_vertical = r1[1] >= r2[3] or r1[3] <= r2[1]
return not (disjoint_horizontal or disjoint_vertical)
rects_and_fields = []
for f in fields["form_fields"]:
rects_and_fields.append(RectAndField(f["label_bounding_box"], "label", f))
rects_and_fields.append(RectAndField(f["entry_bounding_box"], "entry", f))
has_error = False
for i, ri in enumerate(rects_and_fields):
# This is O(N^2); we can optimize if it becomes a problem.
for j in range(i + 1, len(rects_and_fields)):
rj = rects_and_fields[j]
if ri.field["page_number"] == rj.field["page_number"] and rects_intersect(ri.rect, rj.rect):
has_error = True
if ri.field is rj.field:
messages.append(f"FAILURE: intersection between label and entry bounding boxes for `{ri.field['description']}` ({ri.rect}, {rj.rect})")
else:
messages.append(f"FAILURE: intersection between {ri.rect_type} bounding box for `{ri.field['description']}` ({ri.rect}) and {rj.rect_type} bounding box for `{rj.field['description']}` ({rj.rect})")
if len(messages) >= 20:
messages.append("Aborting further checks; fix bounding boxes and try again")
return messages
if ri.rect_type == "entry":
if "entry_text" in ri.field:
font_size = ri.field["entry_text"].get("font_size", 14)
entry_height = ri.rect[3] - ri.rect[1]
if entry_height < font_size:
has_error = True
messages.append(f"FAILURE: entry bounding box height ({entry_height}) for `{ri.field['description']}` is too short for the text content (font size: {font_size}). Increase the box height or decrease the font size.")
if len(messages) >= 20:
messages.append("Aborting further checks; fix bounding boxes and try again")
return messages
if not has_error:
messages.append("SUCCESS: All bounding boxes are valid")
return messages
if __name__ == "__main__":
if len(sys.argv) != 2:
print("Usage: check_bounding_boxes.py [fields.json]")
sys.exit(1)
# Input file should be in the `fields.json` format described in forms.md.
with open(sys.argv[1]) as f:
messages = get_bounding_box_messages(f)
for msg in messages:
print(msg)

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import unittest
import json
import io
from check_bounding_boxes import get_bounding_box_messages
# Currently this is not run automatically in CI; it's just for documentation and manual checking.
class TestGetBoundingBoxMessages(unittest.TestCase):
def create_json_stream(self, data):
"""Helper to create a JSON stream from data"""
return io.StringIO(json.dumps(data))
def test_no_intersections(self):
"""Test case with no bounding box intersections"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 30]
},
{
"description": "Email",
"page_number": 1,
"label_bounding_box": [10, 40, 50, 60],
"entry_bounding_box": [60, 40, 150, 60]
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("SUCCESS" in msg for msg in messages))
self.assertFalse(any("FAILURE" in msg for msg in messages))
def test_label_entry_intersection_same_field(self):
"""Test intersection between label and entry of the same field"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 60, 30],
"entry_bounding_box": [50, 10, 150, 30] # Overlaps with label
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("FAILURE" in msg and "intersection" in msg for msg in messages))
self.assertFalse(any("SUCCESS" in msg for msg in messages))
def test_intersection_between_different_fields(self):
"""Test intersection between bounding boxes of different fields"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 30]
},
{
"description": "Email",
"page_number": 1,
"label_bounding_box": [40, 20, 80, 40], # Overlaps with Name's boxes
"entry_bounding_box": [160, 10, 250, 30]
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("FAILURE" in msg and "intersection" in msg for msg in messages))
self.assertFalse(any("SUCCESS" in msg for msg in messages))
def test_different_pages_no_intersection(self):
"""Test that boxes on different pages don't count as intersecting"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 30]
},
{
"description": "Email",
"page_number": 2,
"label_bounding_box": [10, 10, 50, 30], # Same coordinates but different page
"entry_bounding_box": [60, 10, 150, 30]
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("SUCCESS" in msg for msg in messages))
self.assertFalse(any("FAILURE" in msg for msg in messages))
def test_entry_height_too_small(self):
"""Test that entry box height is checked against font size"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 20], # Height is 10
"entry_text": {
"font_size": 14 # Font size larger than height
}
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("FAILURE" in msg and "height" in msg for msg in messages))
self.assertFalse(any("SUCCESS" in msg for msg in messages))
def test_entry_height_adequate(self):
"""Test that adequate entry box height passes"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 30], # Height is 20
"entry_text": {
"font_size": 14 # Font size smaller than height
}
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("SUCCESS" in msg for msg in messages))
self.assertFalse(any("FAILURE" in msg for msg in messages))
def test_default_font_size(self):
"""Test that default font size is used when not specified"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 20], # Height is 10
"entry_text": {} # No font_size specified, should use default 14
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("FAILURE" in msg and "height" in msg for msg in messages))
self.assertFalse(any("SUCCESS" in msg for msg in messages))
def test_no_entry_text(self):
"""Test that missing entry_text doesn't cause height check"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [60, 10, 150, 20] # Small height but no entry_text
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("SUCCESS" in msg for msg in messages))
self.assertFalse(any("FAILURE" in msg for msg in messages))
def test_multiple_errors_limit(self):
"""Test that error messages are limited to prevent excessive output"""
fields = []
# Create many overlapping fields
for i in range(25):
fields.append({
"description": f"Field{i}",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30], # All overlap
"entry_bounding_box": [20, 15, 60, 35] # All overlap
})
data = {"form_fields": fields}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
# Should abort after ~20 messages
self.assertTrue(any("Aborting" in msg for msg in messages))
# Should have some FAILURE messages but not hundreds
failure_count = sum(1 for msg in messages if "FAILURE" in msg)
self.assertGreater(failure_count, 0)
self.assertLess(len(messages), 30) # Should be limited
def test_edge_touching_boxes(self):
"""Test that boxes touching at edges don't count as intersecting"""
data = {
"form_fields": [
{
"description": "Name",
"page_number": 1,
"label_bounding_box": [10, 10, 50, 30],
"entry_bounding_box": [50, 10, 150, 30] # Touches at x=50
}
]
}
stream = self.create_json_stream(data)
messages = get_bounding_box_messages(stream)
self.assertTrue(any("SUCCESS" in msg for msg in messages))
self.assertFalse(any("FAILURE" in msg for msg in messages))
if __name__ == '__main__':
unittest.main()

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import sys
from pypdf import PdfReader
# Script for Claude to run to determine whether a PDF has fillable form fields. See forms.md.
reader = PdfReader(sys.argv[1])
if (reader.get_fields()):
print("This PDF has fillable form fields")
else:
print("This PDF does not have fillable form fields; you will need to visually determine where to enter data")

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import os
import sys
from pdf2image import convert_from_path
# Converts each page of a PDF to a PNG image.
def convert(pdf_path, output_dir, max_dim=1000):
images = convert_from_path(pdf_path, dpi=200)
for i, image in enumerate(images):
# Scale image if needed to keep width/height under `max_dim`
width, height = image.size
if width > max_dim or height > max_dim:
scale_factor = min(max_dim / width, max_dim / height)
new_width = int(width * scale_factor)
new_height = int(height * scale_factor)
image = image.resize((new_width, new_height))
image_path = os.path.join(output_dir, f"page_{i+1}.png")
image.save(image_path)
print(f"Saved page {i+1} as {image_path} (size: {image.size})")
print(f"Converted {len(images)} pages to PNG images")
if __name__ == "__main__":
if len(sys.argv) != 3:
print("Usage: convert_pdf_to_images.py [input pdf] [output directory]")
sys.exit(1)
pdf_path = sys.argv[1]
output_directory = sys.argv[2]
convert(pdf_path, output_directory)

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import json
import sys
from PIL import Image, ImageDraw
# Creates "validation" images with rectangles for the bounding box information that
# Claude creates when determining where to add text annotations in PDFs. See forms.md.
def create_validation_image(page_number, fields_json_path, input_path, output_path):
# Input file should be in the `fields.json` format described in forms.md.
with open(fields_json_path, 'r') as f:
data = json.load(f)
img = Image.open(input_path)
draw = ImageDraw.Draw(img)
num_boxes = 0
for field in data["form_fields"]:
if field["page_number"] == page_number:
entry_box = field['entry_bounding_box']
label_box = field['label_bounding_box']
# Draw red rectangle over entry bounding box and blue rectangle over the label.
draw.rectangle(entry_box, outline='red', width=2)
draw.rectangle(label_box, outline='blue', width=2)
num_boxes += 2
img.save(output_path)
print(f"Created validation image at {output_path} with {num_boxes} bounding boxes")
if __name__ == "__main__":
if len(sys.argv) != 5:
print("Usage: create_validation_image.py [page number] [fields.json file] [input image path] [output image path]")
sys.exit(1)
page_number = int(sys.argv[1])
fields_json_path = sys.argv[2]
input_image_path = sys.argv[3]
output_image_path = sys.argv[4]
create_validation_image(page_number, fields_json_path, input_image_path, output_image_path)

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import json
import sys
from pypdf import PdfReader
# Extracts data for the fillable form fields in a PDF and outputs JSON that
# Claude uses to fill the fields. See forms.md.
# This matches the format used by PdfReader `get_fields` and `update_page_form_field_values` methods.
def get_full_annotation_field_id(annotation):
components = []
while annotation:
field_name = annotation.get('/T')
if field_name:
components.append(field_name)
annotation = annotation.get('/Parent')
return ".".join(reversed(components)) if components else None
def make_field_dict(field, field_id):
field_dict = {"field_id": field_id}
ft = field.get('/FT')
if ft == "/Tx":
field_dict["type"] = "text"
elif ft == "/Btn":
field_dict["type"] = "checkbox" # radio groups handled separately
states = field.get("/_States_", [])
if len(states) == 2:
# "/Off" seems to always be the unchecked value, as suggested by
# https://opensource.adobe.com/dc-acrobat-sdk-docs/standards/pdfstandards/pdf/PDF32000_2008.pdf#page=448
# It can be either first or second in the "/_States_" list.
if "/Off" in states:
field_dict["checked_value"] = states[0] if states[0] != "/Off" else states[1]
field_dict["unchecked_value"] = "/Off"
else:
print(f"Unexpected state values for checkbox `${field_id}`. Its checked and unchecked values may not be correct; if you're trying to check it, visually verify the results.")
field_dict["checked_value"] = states[0]
field_dict["unchecked_value"] = states[1]
elif ft == "/Ch":
field_dict["type"] = "choice"
states = field.get("/_States_", [])
field_dict["choice_options"] = [{
"value": state[0],
"text": state[1],
} for state in states]
else:
field_dict["type"] = f"unknown ({ft})"
return field_dict
# Returns a list of fillable PDF fields:
# [
# {
# "field_id": "name",
# "page": 1,
# "type": ("text", "checkbox", "radio_group", or "choice")
# // Per-type additional fields described in forms.md
# },
# ]
def get_field_info(reader: PdfReader):
fields = reader.get_fields()
field_info_by_id = {}
possible_radio_names = set()
for field_id, field in fields.items():
# Skip if this is a container field with children, except that it might be
# a parent group for radio button options.
if field.get("/Kids"):
if field.get("/FT") == "/Btn":
possible_radio_names.add(field_id)
continue
field_info_by_id[field_id] = make_field_dict(field, field_id)
# Bounding rects are stored in annotations in page objects.
# Radio button options have a separate annotation for each choice;
# all choices have the same field name.
# See https://westhealth.github.io/exploring-fillable-forms-with-pdfrw.html
radio_fields_by_id = {}
for page_index, page in enumerate(reader.pages):
annotations = page.get('/Annots', [])
for ann in annotations:
field_id = get_full_annotation_field_id(ann)
if field_id in field_info_by_id:
field_info_by_id[field_id]["page"] = page_index + 1
field_info_by_id[field_id]["rect"] = ann.get('/Rect')
elif field_id in possible_radio_names:
try:
# ann['/AP']['/N'] should have two items. One of them is '/Off',
# the other is the active value.
on_values = [v for v in ann["/AP"]["/N"] if v != "/Off"]
except KeyError:
continue
if len(on_values) == 1:
rect = ann.get("/Rect")
if field_id not in radio_fields_by_id:
radio_fields_by_id[field_id] = {
"field_id": field_id,
"type": "radio_group",
"page": page_index + 1,
"radio_options": [],
}
# Note: at least on macOS 15.7, Preview.app doesn't show selected
# radio buttons correctly. (It does if you remove the leading slash
# from the value, but that causes them not to appear correctly in
# Chrome/Firefox/Acrobat/etc).
radio_fields_by_id[field_id]["radio_options"].append({
"value": on_values[0],
"rect": rect,
})
# Some PDFs have form field definitions without corresponding annotations,
# so we can't tell where they are. Ignore these fields for now.
fields_with_location = []
for field_info in field_info_by_id.values():
if "page" in field_info:
fields_with_location.append(field_info)
else:
print(f"Unable to determine location for field id: {field_info.get('field_id')}, ignoring")
# Sort by page number, then Y position (flipped in PDF coordinate system), then X.
def sort_key(f):
if "radio_options" in f:
rect = f["radio_options"][0]["rect"] or [0, 0, 0, 0]
else:
rect = f.get("rect") or [0, 0, 0, 0]
adjusted_position = [-rect[1], rect[0]]
return [f.get("page"), adjusted_position]
sorted_fields = fields_with_location + list(radio_fields_by_id.values())
sorted_fields.sort(key=sort_key)
return sorted_fields
def write_field_info(pdf_path: str, json_output_path: str):
reader = PdfReader(pdf_path)
field_info = get_field_info(reader)
with open(json_output_path, "w") as f:
json.dump(field_info, f, indent=2)
print(f"Wrote {len(field_info)} fields to {json_output_path}")
if __name__ == "__main__":
if len(sys.argv) != 3:
print("Usage: extract_form_field_info.py [input pdf] [output json]")
sys.exit(1)
write_field_info(sys.argv[1], sys.argv[2])

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import json
import sys
from pypdf import PdfReader, PdfWriter
from extract_form_field_info import get_field_info
# Fills fillable form fields in a PDF. See forms.md.
def fill_pdf_fields(input_pdf_path: str, fields_json_path: str, output_pdf_path: str):
with open(fields_json_path) as f:
fields = json.load(f)
# Group by page number.
fields_by_page = {}
for field in fields:
if "value" in field:
field_id = field["field_id"]
page = field["page"]
if page not in fields_by_page:
fields_by_page[page] = {}
fields_by_page[page][field_id] = field["value"]
reader = PdfReader(input_pdf_path)
has_error = False
field_info = get_field_info(reader)
fields_by_ids = {f["field_id"]: f for f in field_info}
for field in fields:
existing_field = fields_by_ids.get(field["field_id"])
if not existing_field:
has_error = True
print(f"ERROR: `{field['field_id']}` is not a valid field ID")
elif field["page"] != existing_field["page"]:
has_error = True
print(f"ERROR: Incorrect page number for `{field['field_id']}` (got {field['page']}, expected {existing_field['page']})")
else:
if "value" in field:
err = validation_error_for_field_value(existing_field, field["value"])
if err:
print(err)
has_error = True
if has_error:
sys.exit(1)
writer = PdfWriter(clone_from=reader)
for page, field_values in fields_by_page.items():
writer.update_page_form_field_values(writer.pages[page - 1], field_values, auto_regenerate=False)
# This seems to be necessary for many PDF viewers to format the form values correctly.
# It may cause the viewer to show a "save changes" dialog even if the user doesn't make any changes.
writer.set_need_appearances_writer(True)
with open(output_pdf_path, "wb") as f:
writer.write(f)
def validation_error_for_field_value(field_info, field_value):
field_type = field_info["type"]
field_id = field_info["field_id"]
if field_type == "checkbox":
checked_val = field_info["checked_value"]
unchecked_val = field_info["unchecked_value"]
if field_value != checked_val and field_value != unchecked_val:
return f'ERROR: Invalid value "{field_value}" for checkbox field "{field_id}". The checked value is "{checked_val}" and the unchecked value is "{unchecked_val}"'
elif field_type == "radio_group":
option_values = [opt["value"] for opt in field_info["radio_options"]]
if field_value not in option_values:
return f'ERROR: Invalid value "{field_value}" for radio group field "{field_id}". Valid values are: {option_values}'
elif field_type == "choice":
choice_values = [opt["value"] for opt in field_info["choice_options"]]
if field_value not in choice_values:
return f'ERROR: Invalid value "{field_value}" for choice field "{field_id}". Valid values are: {choice_values}'
return None
# pypdf (at least version 5.7.0) has a bug when setting the value for a selection list field.
# In _writer.py around line 966:
#
# if field.get(FA.FT, "/Tx") == "/Ch" and field_flags & FA.FfBits.Combo == 0:
# txt = "\n".join(annotation.get_inherited(FA.Opt, []))
#
# The problem is that for selection lists, `get_inherited` returns a list of two-element lists like
# [["value1", "Text 1"], ["value2", "Text 2"], ...]
# This causes `join` to throw a TypeError because it expects an iterable of strings.
# The horrible workaround is to patch `get_inherited` to return a list of the value strings.
# We call the original method and adjust the return value only if the argument to `get_inherited`
# is `FA.Opt` and if the return value is a list of two-element lists.
def monkeypatch_pydpf_method():
from pypdf.generic import DictionaryObject
from pypdf.constants import FieldDictionaryAttributes
original_get_inherited = DictionaryObject.get_inherited
def patched_get_inherited(self, key: str, default = None):
result = original_get_inherited(self, key, default)
if key == FieldDictionaryAttributes.Opt:
if isinstance(result, list) and all(isinstance(v, list) and len(v) == 2 for v in result):
result = [r[0] for r in result]
return result
DictionaryObject.get_inherited = patched_get_inherited
if __name__ == "__main__":
if len(sys.argv) != 4:
print("Usage: fill_fillable_fields.py [input pdf] [field_values.json] [output pdf]")
sys.exit(1)
monkeypatch_pydpf_method()
input_pdf = sys.argv[1]
fields_json = sys.argv[2]
output_pdf = sys.argv[3]
fill_pdf_fields(input_pdf, fields_json, output_pdf)

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import json
import sys
from pypdf import PdfReader, PdfWriter
from pypdf.annotations import FreeText
# Fills a PDF by adding text annotations defined in `fields.json`. See forms.md.
def transform_coordinates(bbox, image_width, image_height, pdf_width, pdf_height):
"""Transform bounding box from image coordinates to PDF coordinates"""
# Image coordinates: origin at top-left, y increases downward
# PDF coordinates: origin at bottom-left, y increases upward
x_scale = pdf_width / image_width
y_scale = pdf_height / image_height
left = bbox[0] * x_scale
right = bbox[2] * x_scale
# Flip Y coordinates for PDF
top = pdf_height - (bbox[1] * y_scale)
bottom = pdf_height - (bbox[3] * y_scale)
return left, bottom, right, top
def fill_pdf_form(input_pdf_path, fields_json_path, output_pdf_path):
"""Fill the PDF form with data from fields.json"""
# `fields.json` format described in forms.md.
with open(fields_json_path, "r") as f:
fields_data = json.load(f)
# Open the PDF
reader = PdfReader(input_pdf_path)
writer = PdfWriter()
# Copy all pages to writer
writer.append(reader)
# Get PDF dimensions for each page
pdf_dimensions = {}
for i, page in enumerate(reader.pages):
mediabox = page.mediabox
pdf_dimensions[i + 1] = [mediabox.width, mediabox.height]
# Process each form field
annotations = []
for field in fields_data["form_fields"]:
page_num = field["page_number"]
# Get page dimensions and transform coordinates.
page_info = next(p for p in fields_data["pages"] if p["page_number"] == page_num)
image_width = page_info["image_width"]
image_height = page_info["image_height"]
pdf_width, pdf_height = pdf_dimensions[page_num]
transformed_entry_box = transform_coordinates(
field["entry_bounding_box"],
image_width, image_height,
pdf_width, pdf_height
)
# Skip empty fields
if "entry_text" not in field or "text" not in field["entry_text"]:
continue
entry_text = field["entry_text"]
text = entry_text["text"]
if not text:
continue
font_name = entry_text.get("font", "Arial")
font_size = str(entry_text.get("font_size", 14)) + "pt"
font_color = entry_text.get("font_color", "000000")
# Font size/color seems to not work reliably across viewers:
# https://github.com/py-pdf/pypdf/issues/2084
annotation = FreeText(
text=text,
rect=transformed_entry_box,
font=font_name,
font_size=font_size,
font_color=font_color,
border_color=None,
background_color=None,
)
annotations.append(annotation)
# page_number is 0-based for pypdf
writer.add_annotation(page_number=page_num - 1, annotation=annotation)
# Save the filled PDF
with open(output_pdf_path, "wb") as output:
writer.write(output)
print(f"Successfully filled PDF form and saved to {output_pdf_path}")
print(f"Added {len(annotations)} text annotations")
if __name__ == "__main__":
if len(sys.argv) != 4:
print("Usage: fill_pdf_form_with_annotations.py [input pdf] [fields.json] [output pdf]")
sys.exit(1)
input_pdf = sys.argv[1]
fields_json = sys.argv[2]
output_pdf = sys.argv[3]
fill_pdf_form(input_pdf, fields_json, output_pdf)